using System;

public class Program

{

    public static void Main()

    {

        //Console.WriteLine("Framework version: "+ Environment.Version.ToString());

        Console.WriteLine("Without fix, 2nd catch shows a different line\n");

        throwAndRethrowException(false);

        Console.WriteLine("\n");

        Console.WriteLine("With fix, 2nd catch shows the same line\n");

        throwAndRethrowException(true);

    }

    //Thorws an excepton, catches it, and than rethrows. According to MSDN, rethrowing with "throw;" should preserve the stacktrace

    //But if the exception is rehtrown in the same method it was first throw, the stacktrace is lost. (seems to be a bug in .net)

    static void throwAndRethrowException(bool usePreserveStacktraceFix){

        try{

            try{

                //Original exception

                throw new Exception("Shalalala");

            }catch(Exception ex){

                //Exception catched for the first time, stack is correct

                Console.WriteLine("1st catch:"+ex.StackTrace);

                if(usePreserveStacktraceFix){

                    RethrowExceptionButPreserveStackTrace(ex);

                }

                    else{

                    //rethrow, just as in the book

                    //this should preserve the stacktrace, but it does not

                    throw;

                }

            }

        }

        catch(Exception ex){

        //Catch the rethrowed exception

        //The stack points to the last line of the funciton in which the exception was thrown.

        Console.WriteLine("2nd catch:"+ex.StackTrace);;

        }

    }

    //Fix to rethrow an exception, and really preserve the stacktrace

    private static void RethrowExceptionButPreserveStackTrace(Exception exception)

    {

      System.Reflection.MethodInfo preserveStackTrace = typeof(Exception).GetMethod("InternalPreserveStackTrace",

        System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);

      preserveStackTrace.Invoke(exception, null);

        throw exception;

    }

}